The prevalence of comorbid substance use disorders and serious mental illnesses in prisons
Authors: Verity Wainwright, Alice Dawson
Journal: The Lancet Public Health (2022)

The mental health of people in prison remains a public health priority, with a high prevalence of mental illness among prison populations globally.1Fazel S Hayes AJ Bartellas K Clerici M Trestman R Mental health of prisoners: prevalence, adverse outcomes, and interventions.Lancet Psychiatry. 2016; 3: 871-881Summary Full Text Full Text PDF PubMed Scopus (380) Google Scholar Comorbidity (ie, the coexistence of two or more mental health diagnoses) is also common, particularly with alcohol and substance use, and the population with dual disorders present considerable challenges in custody and on release.2Peters R Wexler HK Lurigio AJ Co-occurring substance use and mental disorders in the criminal justice system: a new frontier of clinical practice and research.Psychiatr Rehabil J. 2015; 38: 1-6Crossref PubMed Scopus (58) Google Scholar Imprisonment offers an opportunity to identify and treat mental illnesses and substance use disorders to improve outcomes for this population. Gergő Baranyi and colleagues3Baranyi G Fazel S Delhey Langerfeldt S Mundt AP The prevalence of comorbid serious mental illnesses and substance use disorders in prison populations: a systematic review and meta-analysis.Lancet Public Health. 2022; 7: e557-e568Summary Full Text Full Text PDF Scopus (2) Google Scholar extend our understanding of the clinical picture in prison by being the first to comprehensively look at the prevalence of comorbid serious mental illnesses and substance use disorders (dual disorders). Their systematic review and meta-analysis reports on both the current and lifetime prevalence of dual disorders among people in prison across 21 countries and includes data from 16 unpublished studies. The headline from this study is that there is a high prevalence of dual disorders among people in prison. About half of the total studied population with current non-affective psychosis (49·2%) or major depression (51·6%) also had substance use disorders. This finding has implications for assessment procedures, highlighting a need for more routine and comprehensive screening to capture individuals with dual disorders to inform appropriate treatment pathways. The identification of mental health issues in prison remains problematic; screening on reception into prison only captures a quarter of mental health need.4Senior J Birmingham L Harty MA et al.Identification and management of prisoners with severe psychiatric illness by specialist mental health services.Psychol Med. 2013; 43: 1511-1520Crossref PubMed Scopus (65) Google Scholar Those with comorbidities are also probably at higher risk of falling through service gaps given that substance use can mask mental health issues. Improving processes for earlier identification for this population has the potential to improve treatment outcomes. There are additional questions that need to be addressed to further inform this area of knowledge. Dual disorders are more common among women than among men; women were over-represented in the pooled total population of this study compared with the demographics of the global prison population (30·6% vs 7%),5Walmsley R World female imprisonment list (fourth edition).https://www.prisonstudies.org/sites/default/files/resources/downloads/world_female_prison_4th_edn_v4_web.pdfDate: 2017Date accessed: April 23, 2022Google Scholar highlighting that data are available for further work focusing on women specifically. Furthermore, dual disorders are also more common among survivors of abuse and there is already firm support for a link between trauma and substance misuse among women in prison.6Tripodi SJ Pettus-Davis C Histories of childhood victimization and subsequent mental health problems, substance use, and sexual victimization for a sample of incarcerated women in the US.Int J Law Psychiatry. 2013; 36: 30-40Crossref PubMed Scopus (132) Google Scholar Although the authors discuss implications for assessment and treatment generally, future work could help to inform a gender-responsive approach, given that the needs and experiences of women in prison are different to those of men7Bartlett A Hollins S Challenges and mental health needs of women in prison.Br J Psychiatry. 2018; 212: 134-136Crossref PubMed Scopus (28) Google Scholar and that women experience drug addiction differently to men.8Zlebnik NE Females pay a higher price for addiction.Neuropsychopharmacology. 2019; 44: 1179-1181Crossref PubMed Scopus (7) Google Scholar Another area for further work, recognised by the authors themselves, regards suicide risk. Suicide is the leading cause of death in prisons worldwide and dual disorders have been linked with an increased risk of suicide in national and regional prison samples.9,10 We reiterate that there is a clear need for future research to explore this link and the relationship between mental health, substance misuse, and suicide risk. The better understanding of dual disorders that this study offers helps to inform treatment needs and approaches. The results suggest that better integration between substance misuse services and mental health services could improve overall treatment effectiveness. However, how this integration is operationalised when provision is often split among several different public, private, and charitable organisations needs further consideration. Staff on the frontline often report difficulties regarding effective collaboration and joint working between services. For example, in England, the National Health Service has separate diagnostic and treatment pathways for those presenting with mental health needs and substance use disorders, but, arguably, services for those with dual disorders could be integrated at a commissioning level. Learning more about the prevalence of dual disorders further emphasises how siloed working might impact patients. Further research could add to some much needed practical recommendations around improving a combined treatment pathway for this population. We declare no competing interests. The views expressed in this Comment are those of the authors and do not necessarily represent those of their institutions. This online publication has been corrected. The corrected version first appeared at thelancet.com/public-health on June 29, 2022 This online publication has been corrected. The corrected version first appeared at thelancet.com/public-health on June 29, 2022 The prevalence of comorbid serious mental illnesses and substance use disorders in prison populations: a systematic review and meta-analysisAround half of the prison population with non-affective psychosis or major depression have a comorbid substance use disorder. Consideration should be given to screening for dual disorders and implementing integrated and scalable treatments. Full-Text PDF Open AccessCorrection to Lancet Public Health 2022; 7: e492–93Wainwright V, Dawson A. The prevalence of comorbid substance use disorders and serious mental illnesses in prisons. Lancet Public Health 2022; 7: e492–93—In this Linked Comment, Alice Dawson's affiliation should have been "Her Majesty's Prison and Probation Service, Ministry of Justice, Manchester, UK" and the following disclaimer has been added: "The views expressed in this Comment are those of the authors and do not necessarily represent those of their institutions". These corrections have been made as of June 29, 2022. Full-Text PDF Open Access